Many modern civilian and military aircraft are dependent upon electrical systems for proper operation. Often, miles of wires interconnect the electrical systems within an aircraft. During the life of the aircraft, these wires are subject to vibration, corrosion, aging, and other stresses.
Failure of a wire or set of wires in an aircraft wire harness may result in a spectrum of events ranging from the malfunction of a simple light bulb to the malfunction of an aircraft system. As an aircraft ages, wire related maintenance costs and related interruptions in service of the aircraft for wire repair can be costly and can occur with increasing frequency.
In general, it is not practical to remove an aircraft wire harness from an aircraft for inspection. As well as being costly and time consuming, re-installing a wire harness after a successful test may stress and strain the wire harness and induce other unknown wire faults. Therefore, to minimize aircraft downtime, cost and overall complexity, it is generally desirable to test an aircraft wire harness without removing it from the aircraft.
With the amount of wire generally contained in an aircraft, the presence of insulation generally covering the wires, and aircraft parts covering the insulated wires and wire harnesses, electrical connectivity testing may be selectively used in addition to selective visual inspections.
To facilitate connections between systems, some wire harnesses employ military specification electrical connectors. Military specification connectors are designed to withstand stress and/or to provide protection for the integrity of the electrical connection against many factors commonly including weather, moisture, altitude, pressure, vibration, temperature, etc. . . . all of which may cause connectivity failure during operation and/or permit deterioration and/or corrosion of the connection contacts.
To provide a robust and functional connection, a military specification electrical connector generally is manufactured to certain standards that provide: A) protection of the electrical connection; B) proper alignment of the connection; and C) a firm engagement by the connector beyond a mere friction hold.
The connectivity an aircraft wire harness may be tested by attaching test equipment with corresponding mating military specification connectors (See FIG. 1A.) to the wire harness. In this manner, a connector on the test equipment wire harness may be mated to a connector on the aircraft harness to be tested. The process of connecting a military specification connector to a test equipment wire harness may be a complex process that may involve specialized tooling, training, and time consuming assembly processes.
FIG. 1 A shows one prior art military specification electrical aircraft connector 7 for aircraft wire harnesses. The military connector has a hard metal backshell 9, a metal shield 15, a slot 17 and a lock mechanism 19. The metal backshell 9 protects the harness wires 11 at their point of connection to the roots (not shown) of the connector's pins or sockets 13, and provides a grasping point. The metal shield 15 protects the contact pins or sockets 13. The slot 17 is a physical alignment device that permits the connector 7 to be joined to a mating connector in an aligned orientation. The connection lock mechanism, such as a threaded coupling 19 serves to securely engage one military specification connector to a mating military specification connector in a specific robust alignment. As shown, the backshell 9 of military specification electrical connector 7 can incorporate a compression clamp 21 for securing the backshell 9, and thus the connector 7, to the wire harness 11.
Specialized tooling and manufacturing processes are used to make a military specification electrical connector. Such rigorous tooling and manufacturing requirements are reflected in the costs of military specification connectors, with per connector costs ranging from several hundred to thousands of dollars.
Fabricating a test harness with military specification connectors can become an arduous and expensive task because the wire harness for a typical auxiliary power supply may have as many as a dozen military specification electrical connectors. In addition, the number of military specification electrical connectors within a given aircraft may number in the hundreds if not in the thousands. Further, different aircraft and different versions of aircraft generally have different military specification electrical connectors. With the wide variety of military specification electrical connectors in use, it is expensive to maintain an inventory of pre-assembled test purpose wire harnesses. In addition, the high cost of the military specification electrical connectors makes disposal of the entire test harness after use undesirable. It is therefore a practice to disassemble the test harness so the military specification connectors can be reused. This can be time consuming and expensive.
With high costs, bulky size, specialized attachment processes, and time consuming coupling and de-coupling to test wires, maintaining an inventory of military specification electrical connectors for use in testing aircraft wire harness can be wasteful of time and resources.
Hence, there is a need for a test-purpose connector, and a related method of assembly, for use with military specification electrical aircraft connectors, that overcomes one or more of the drawbacks identified above. The present invention satisfies one or more of these needs.